Warrior Met Coal (HCC) 10-Q 1 May 24 2024 Q1 Quarterly report Financial data

Cover

Cover - shares	3 Months Ended
	Mar. 31, 2024	Apr. 29, 2024
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2024
Document Transition Report	false
Entity File Number	001-38061
Entity Registrant Name	Warrior Met Coal, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	81-0706839
Entity Address, Address Line One	16243 Highway 216
Entity Address, City or Town	Brookwood
Entity Address, State or Province	AL
Entity Address, Postal Zip Code	35444
City Area Code	205
Local Phone Number	554-6150
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)		52,300,707
Entity Central Index key	0001691303
Document Fiscal Year Focus	2024
Amendment Flag	false
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31
Common Stock
Document Information [Line Items]
Title of 12(b) Security	Common Stock, par value $.01 per share
Trading Symbol	HCC
Security Exchange Name	NYSE
Preferred Stock
Document Information [Line Items]
Title of 12(b) Security	Rights to Purchase Series A Junior Participating Preferred Stock, par value $0.01 per share
Security Exchange Name	NYSE
No Trading Symbol Flag	true

CONDENSED STATEMENTS OF OPERATI

CONDENSED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenues:
Total revenues	$ 503,512	$ 509,674
Costs and expenses:
Cost of sales (exclusive of items shown separately below)	285,587	232,630
Cost of other revenues (exclusive of items shown separately below)	9,965	11,438
Depreciation and depletion	40,023	37,213
Selling, general and administrative	18,658	14,516
Business interruption	201	4,217
Total costs and expenses	354,434	300,014
Operating income	149,078	209,660
Interest expense	(1,121)	(7,443)
Interest income	8,154	8,903
Other income	0	221
Income before income tax expense	156,111	211,341
Income tax expense	19,122	29,064
Net income	$ 136,989	$ 182,277
Basic and diluted net income per share:
Net income per share-basic (in dollars per share)	$ 2.63	$ 3.52
Net income per share-diluted (in dollars per share)	$ 2.62	$ 3.51
Weighted average number of shares outstanding-basic (in shares)	52,163	51,842
Weighted average number of shares outstanding-diluted (in shares)	52,217	51,956
Dividends per share (in dollars per share)	$ 0.58	$ 0.95
Sales
Revenues:
Total revenues	$ 497,998	$ 500,491
Other revenues
Revenues:
Total revenues	$ 5,514	$ 9,183

CONDENSED BALANCE SHEETS

CONDENSED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 693,858	$ 738,197
Short-term investments	9,149	9,030
Trade accounts receivable	213,400	98,225
Income tax receivable	0	7,833
Inventories, net	165,650	183,949
Prepaid expenses and other receivables	37,200	31,932
Total current assets	1,119,257	1,069,166
Mineral interests, net	78,428	80,442
Property, plant and equipment, net	1,253,395	1,179,609
Non-current income tax receivable	0	0
Deferred income taxes	5,752	5,854
Other long-term assets	21,759	21,987
Total assets	2,478,591	2,357,058
Current liabilities:
Accounts payable	43,184	36,245
Accrued expenses	80,944	81,612
Asset retirement obligations	12,500	12,500
Short-term financing lease liabilities	11,357	11,463
Other current liabilities	15,057	5,850
Current portion of long-term debt	0	0
Total current liabilities	163,042	147,670
Long-term debt	153,166	153,023
Asset retirement obligations	71,916	71,666
Black Lung obligations	27,125	26,966
Long-term financing lease liabilities	7,708	8,756
Deferred income taxes	77,434	74,531
Other long-term liabilities	0	0
Total liabilities	500,391	482,612
Stockholders’ Equity:
Common stock, $0.01 par value, (140,000,000 shares authorized as of March 31, 2024 and December 31, 2023; 54,519,114 issued and 52,297,273 outstanding as of March 31, 2024; 54,240,764 issued and 52,018,923 outstanding as of December 31, 2023)	545	542
Preferred stock, $0.01 par value per share (10,000,000 shares authorized; no shares issued and outstanding)	0	0
Treasury stock, at cost (2,221,841 shares as of March 31, 2024 and December 31, 2023)	(50,576)	(50,576)
Additional paid in capital	276,731	279,332
Retained earnings	1,751,500	1,645,148
Total stockholders’ equity	1,978,200	1,874,446
Total liabilities and stockholders’ equity	$ 2,478,591	$ 2,357,058

CONDENSED BALANCE SHEETS (Paren

CONDENSED BALANCE SHEETS (Parenthetical) - $ / shares	Mar. 31, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock authorized (in shares)	140,000,000	140,000,000
Common stock issued (in shares)	54,519,114	54,240,764
Common stock outstanding (in shares)	52,297,273	52,018,923
Preferred stock outstanding (in shares)	0	0
Preferred stock issued (in shares)	0	0
Preferred stock authorized (in shares)	10,000,000	10,000,000
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Treasury stock (in shares)	2,221,841	2,221,841

CONDENSED STATEMENTS OF CHANGES

CONDENSED STATEMENTS OF CHANGES IN STOCKHOLDERS’ EQUITY - USD ($) $ in Thousands	Total	Common Stock	Preferred Stock	Treasury Stock	Additional Paid in Capital	Retained Earnings
Balance, beginning of period at Dec. 31, 2022		$ 539	$ 0	$ (50,576)	$ 269,956	$ 1,227,596
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of shares		0
Stock based compensation expense					7,713
Net income	$ 182,277					182,277
Dividends paid						(50,016)
Tax withholdings on vested equity awards					(9,198)
Balance, end of period at Mar. 31, 2023	1,578,291	539	0	(50,576)	268,471	1,359,857
Balance, beginning of period at Dec. 31, 2023	1,874,446	542	0	(50,576)	279,332	1,645,148
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of shares		3
Stock based compensation expense					9,179
Net income	136,989					136,989
Dividends paid						(30,638)
Tax withholdings on vested equity awards					(11,779)
Balance, end of period at Mar. 31, 2024	$ 1,978,200	$ 545	$ 0	$ (50,576)	$ 276,732	$ 1,751,499

CONDENSED STATEMENTS OF CASH FL

CONDENSED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
OPERATING ACTIVITIES
Net income	$ 136,989	$ 182,277
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and depletion	40,023	37,213
Deferred income tax expense	2,909	29,064
Stock based compensation expense	9,152	7,702
Amortization of debt issuance costs and debt discount	393	713
Accretion of asset retirement obligations	1,297	906
Mark-to-market gain on gas hedges	0	(500)
Changes in operating assets and liabilities:
Trade accounts receivable	(115,175)	(56,804)
Income tax receivable	7,833	0
Inventories	16,162	17,406
Prepaid expenses and other receivables	(5,267)	(3,140)
Accounts payable	5,631	(8,463)
Accrued expenses and other current liabilities	5,046	(18,032)
Other	(935)	4,592
Net cash provided by operating activities	104,058	192,934
INVESTING ACTIVITIES
Purchase of property, plant and equipment	(99,703)	(68,179)
Deferred mine development costs	(1,987)	(14,458)
Acquisition of gas well ownership interest	0	(2,381)
Net cash used in investing activities	(101,690)	(85,018)
FINANCING ACTIVITIES
Dividends paid	(30,638)	(50,016)
Retirements of debt	0	(8,000)
Principal repayments of finance lease obligations	(4,292)	(7,634)
Payments for taxes related to net share settlement of equity awards	(11,777)	(9,198)
Net cash used in financing activities	(46,707)	(74,848)
Net (decrease) increase in cash and cash equivalents	(44,339)	33,068
Cash and cash equivalents at beginning of period	738,197	829,480
Cash and cash equivalents at end of period	$ 693,858	$ 862,548

Business and Basis of Presentat

Business and Basis of Presentation	3 Months Ended
	Mar. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Business and Basis of Presentation	Business and Basis of Presentation Description of the Business Warrior Met Coal, Inc. (the "Company") is a U.S.-based, environmentally and socially minded supplier to the global steel industry. The Company is dedicated entirely to mining non-thermal met steelmaking coal used as a critical component of steel production by metal manufacturers in Europe, South America and Asia. The Company is a large-scale, low-cost producer and exporter of premium quality met coal, also known as hard-coking coal ("HCC"), operating highly efficient longwall operations in its underground mines based in Alabama. The HCC that the Company produces from the Blue Creek coal seam contains very low sulfur and has strong coking properties. The Company also generates ancillary revenues from the sale of natural gas extracted as a byproduct from the underground coal mines and royalty revenues from leased properties. Basis of Presentation The accompanying financial statements are presented in accordance with accounting principles generally accepted in the United States (“GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In our opinion, the financial statements include all adjustments (consisting of normal recurring accruals) necessary in order to make the financial statements not misleading. For further information, refer to the financial statements and related notes included in the Company's Annual Report on Form 10-K for the year ended December 31, 2023 (the "2023 Annual Report"). Operating results for the three months ended March 31, 2024 are not necessarily indicative of the final results that may be expected for the year ended December 31, 2024. The balance sheet at December 31, 2023 has been derived from the audited financial statements for the year ended December 31, 2023 included in the 2023 Annual Report. Collective Bargaining Agreement The Company's Collective Bargaining Agreement ("CBA") with the labor union representing certain of the Company's hourly employees expired on April 1, 2021 and the labor union initiated a strike after an agreement on a new contract was not reached. As a result of the strike, the Company initially idled Mine No. 4 and scaled back operations at Mine No. 7. In the first quarter of 2022, the Company restarted operations at Mine No. 4. On February 16, 2023, the labor union representing certain of the Company's hourly employees announced that they were ending the strike and made an unconditional offer to return to work. The Company incurred business interruption expenses of approximately $0.2 million for the three months ended March 31, 2024, which represent ongoing legal expenses associated with ongoing labor negotiations. The Company incurred $4.2 million for the three months ended March 31, 2023, which represent non-recurring expenses that were directly attributable to the labor strike for incremental safety and security, labor negotiations and other expenses. These expenses are presented separately in the Condensed Statements of Operations. The Company continues to engage in good faith efforts with the labor union to reach an agreement on a new contract. Acquisitions On March 31, 2023, the Company acquired the remaining ownership interest in gas wells owned by an independent third party for $2.4 million. The purchase consideration was allocated to the assets acquired and liabilities assumed based upon their estimated fair values at the date of acquisition. The acquisition is not deemed to be material to the condensed financial statements.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2024
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies The Company's significant accounting policies are consistent with those disclosed in Note 2 to its audited financial statements included in the 2023 Annual Report. Use of Estimates The Company prepares its financial statements in conformity with GAAP, which requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the periods presented. Due to the inherent uncertainty involved in making estimates, actual results could differ from those estimates. Cash and Cash Equivalents Cash and cash equivalents include short-term deposits and highly liquid investments that have original maturities of three months or less when purchased and are stated at cost, which approximates fair value. Short-Term Investments Instruments with maturities greater than three months, but less than twelve months, are included in short-term investments. The Company also purchases fixed income securities and certificates of deposits with varying maturities that are classified as available for sale and are carried at fair value. Securities classified as held to maturity are those securities that management has the intent and ability to hold to maturity. As of March 31, 2024 and December 31, 2023, short-term investments consisted of $9.1 million and $9.0 million in cash and fixed income securities. The short-term investments are posted as collateral for the self-insured black lung related claims asserted by or on behalf of former employees of Walter Energy, Inc. ("Walter Energy") and its subsidiaries, which were assumed by the Company and relate to periods prior to March 31, 2016. Revenue Recognition Revenue is recognized when performance obligations under the terms of a contract with the Company's customers are satisfied; for all contracts this occurs when control of the promised goods have been transferred to the Company's customers and risk of loss passes such customers. For coal shipments to domestic customers via rail, control is transferred when the railcar is loaded. For coal shipments to international customers via ocean vessel, control is transferred when the vessel is loaded at the Port of Mobile in Alabama. Occasionally, the Company will sell coal stockpiles at the barge loadout or port upon which control, title and risk of loss transfers when stockpiles are segregated. For all steelmaking coal sales under average pricing contracts where pricing is not finalized when revenue is recognized, revenue is recorded based on estimated consideration to be received at the date of the sale. For natural gas sales, control is transferred when the gas has been transferred to the pipeline. Revenue is disaggregated between coal sales within the Company's mining segment and natural gas sales included in all other revenues, as disclosed in Note 12. The Company's coal and gas sales generally include up to 45-day payment terms following the transfer of control of the goods to the customer. The Company typically does not include extended payment terms in its contracts with customers. Trade Accounts Receivable and Allowance for Credit Losses Trade accounts receivable are stated at cost. Trade accounts receivable represent customer obligations that are derived from revenue recognized from contracts with customers. Credit is extended based on an evaluation of the individual customer's financial condition. The Company maintains trade credit insurance on the majority of its customers and the geographic regions of coal shipments to these customers. In some instances, the Company requires letters of credit, cash collateral or prepayments from its customers on or before shipment to mitigate the risk of loss. These efforts have consistently resulted in the Company recognizing no historical credit losses. The Company also has never had to have a claim against its trade credit insurance policy. In order to estimate the allowance for credit losses on trade accounts receivable, the Company utilizes an aging approach in which potential impairment is calculated based on how long a receivable has been outstanding (e.g., current, 1-31 days, 31-60 days, etc.). The Company calculates an expected credit loss rate based on the Company’s historical credit loss rate, the risk characteristics of its customers, and the current steelmaking coal and steel market environments. As of March 31, 2024 and December 31, 2023, the estimated allowance for credit losses was immaterial and did not have a material impact on the Company's financial statements.

Inventories, net

Inventories, net	3 Months Ended
	Mar. 31, 2024
Inventory Disclosure [Abstract]
Inventories, net	Inventories, net Inventories, net are summarized as follows (in thousands): March 31, 2024 December 31, 2023 Coal $ 110,438 $ 129,989 Raw materials, parts, supplies and other, net 55,212 53,960 Total inventories, net $ 165,650 $ 183,949

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2024
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes For the three months ended March 31, 2024 and 2023, the Company estimated its annual effective tax rate and applied this effective tax rate to its year-to-date pretax income at the end of the interim reporting period. The tax effect of unusual or infrequently occurring items, including the effects of changes in tax laws or rates and changes in judgment about the realizability of deferred tax assets, are reported in the interim period in which they occur. For the three months ended March 31, 2024 and 2023, the Company had income tax expense of $19.1 million and $29.1 million, respectively.

Debt

Debt	3 Months Ended
	Mar. 31, 2024
Debt Disclosure [Abstract]
Debt	Debt The Company's debt consisted of the following (in thousands): March 31, 2024 December 31, 2023 Weighted Average Interest Rate Final Maturity Senior Secured Notes $ 156,517 $ 156,517 7.875% December 2028 ABL Borrowings — — Varies (1) December 2026 Debt discount (3,351) (3,494) Total debt 153,166 153,023 Less: current debt — — Total long-term debt $ 153,166 $ 153,023 (1) Borrowings under the ABL Facility bear interest at a rate equal to Secured Overnight Financing Rate ("SOFR") ranging from 1.5% to 2.0%, plus a credit adjustment spread, ranging currently from 0.11448% to 0.42826%, or an alternate base rate plus an applicable margin, which is determined based on the average availability of the commitments under the ABL Facility, ranging from 0.5% to 1.0%. Senior Secured Notes On December 6, 2021, the Company issued $350.0 million in aggregate principal amount of 7.875% senior secured notes due 2028 (the “Notes”) at an initial price of 99.343% of their face amount. The Notes were issued to qualified institutional buyers pursuant to Rule 144A under the Securities Act of 1933, as amended (the “Securities Act”), and to certain non-U.S. persons in transactions outside the United States in accordance with Regulation S under the Securities Act. The Company used the net proceeds of the offering of the Notes, together with cash on hand, to fund the redemption of all of the Company’s outstanding 8.00% senior secured notes due 2024 (the “Existing Notes”), including payment of the redemption premium in connection with such redemption. The Notes will mature on December 1, 2028. During the three months ended March 31, 2023, the Company repurchased in the open market and extinguished approximately $8.0 million principal amount of our Notes. In connection with the extinguishment of our Notes, we recognized a loss on early extinguishment of debt of $0.1 million which is included in interest expense in the Condensed Statements of Operations. ABL Facility On December 6, 2021, the Company entered into the Second Amended and Restated Asset-Based Revolving Credit Agreement (the “Second Amended and Restated Credit Agreement”), by and among the Company and certain of its subsidiaries, as borrowers, the guarantors party thereto, the lenders from time to time party thereto and Citibank, as administrative agent (in such capacity, the "Agent"), which amends and restates in its entirety the then existing Amended and Restated Asset-Based Revolving Credit Agreement (as amended, the “ABL Facility”). The Second Amended and Restated Credit Agreement, among other things, (i) extended the maturity date of the ABL Facility to December 6, 2026; (ii) changed the calculation of the interest rate payable on borrowings from being based on a London Inter-Bank Offered Rate to be based on a SOFR, with corresponding changes to the applicable interest rate margins with respect to such borrowings, (iii) amended certain definitions related to the calculation of the borrowing base; (iv) increased the commitments that may be used to issue letters of credit to $65.0 million; and (v) amended certain baskets contained in the covenants to conform to the baskets contained in the indenture governing the Notes (the "Indenture"). The Second Amended and Restated Credit Agreement also allows the Company to borrow up to $116.0 million through November 2026, subject to availability under the borrowing base and other conditions. As of March 31, 2024, no loans were outstanding under the ABL Facility and there were $8.7 million of letters of credit issued and outstanding under the ABL Facility. At March 31, 2024, the Company had $107.4 million of availability under the ABL Facility (calculated net of $8.7 million of letters of credit outstanding at such time).

Leases

Leases	3 Months Ended
	Mar. 31, 2024
Leases [Abstract]
Leases	Leases The Company primarily enters into rental agreements for certain mining equipment that are for periods of 12 months or less, some of which include options to extend the leases. Leases that are for periods of 12 months or less are not recorded on the balance sheet. The Company recognizes lease expense on these agreements on a straight-line basis over the lease term. Additionally, the Company has certain finance leases for mining equipment that expire over various contractual periods. These leases have remaining lease terms of one Supplemental balance sheet information related to leases was as follows (in thousands): March 31, 2024 December 31, 2023 Finance lease right-of-use assets, net (1) $ 64,406 $ 67,014 Finance lease liabilities Current 11,357 11,463 Noncurrent 7,708 8,756 Total finance lease liabilities $ 19,065 $ 20,219 Weighted average remaining lease term - finance leases (in months) 20.0 20.8 Weighted average discount rate - finance leases (2) 7.02 % 7.02 % (1) Finance lease right-of-use assets are recorded net of accumulated amortization of $42.2 million and $38.5 million and are included in property, plant and equipment, net in the Condensed Balance Sheets as of March 31, 2024 and the Balance Sheets as of December 31, 2023, respectively. (2) When an implicit discount rate is not readily available in a lease, the Company uses its incremental borrowing rate based on information available at the commencement date when determining the present value of lease payments. The components of lease expense were as follows (in thousands): For the three months ended March 31, 2024 2023 Operating lease cost (1) : $ 12,606 $ 6,430 Finance lease cost: Amortization of leased assets 5,758 5,280 Interest on lease liabilities 351 638 Net lease cost $ 18,715 $ 12,348 (1) Includes leases that are for periods of 12 months or less. Maturities of lease liabilities for the Company's finance leases as of March 31, 2024 were as follows (in thousands): Finance Leases (1) 2024 $ 14,208 2025 4,598 2026 1,052 2027 — Thereafter — Total 19,858 Less: amount representing interest (793) Present value of lease liabilities $ 19,065 (1) Finance lease payments include $3.0 million of future payments required under signed lease agreements that have not yet commenced. Supplemental cash flow information related to the Company's leases was as follows (in thousands): For the three months ended March 31, 2024 2023 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from finance leases $ 351 $ 638 Financing cash flows from finance leases $ 4,292 $ 7,634 Non-cash right-of-use assets obtained in exchange for lease obligations: Finance leases $ 3,138 $ 2,158
Leases	Leases The Company primarily enters into rental agreements for certain mining equipment that are for periods of 12 months or less, some of which include options to extend the leases. Leases that are for periods of 12 months or less are not recorded on the balance sheet. The Company recognizes lease expense on these agreements on a straight-line basis over the lease term. Additionally, the Company has certain finance leases for mining equipment that expire over various contractual periods. These leases have remaining lease terms of one Supplemental balance sheet information related to leases was as follows (in thousands): March 31, 2024 December 31, 2023 Finance lease right-of-use assets, net (1) $ 64,406 $ 67,014 Finance lease liabilities Current 11,357 11,463 Noncurrent 7,708 8,756 Total finance lease liabilities $ 19,065 $ 20,219 Weighted average remaining lease term - finance leases (in months) 20.0 20.8 Weighted average discount rate - finance leases (2) 7.02 % 7.02 % (1) Finance lease right-of-use assets are recorded net of accumulated amortization of $42.2 million and $38.5 million and are included in property, plant and equipment, net in the Condensed Balance Sheets as of March 31, 2024 and the Balance Sheets as of December 31, 2023, respectively. (2) When an implicit discount rate is not readily available in a lease, the Company uses its incremental borrowing rate based on information available at the commencement date when determining the present value of lease payments. The components of lease expense were as follows (in thousands): For the three months ended March 31, 2024 2023 Operating lease cost (1) : $ 12,606 $ 6,430 Finance lease cost: Amortization of leased assets 5,758 5,280 Interest on lease liabilities 351 638 Net lease cost $ 18,715 $ 12,348 (1) Includes leases that are for periods of 12 months or less. Maturities of lease liabilities for the Company's finance leases as of March 31, 2024 were as follows (in thousands): Finance Leases (1) 2024 $ 14,208 2025 4,598 2026 1,052 2027 — Thereafter — Total 19,858 Less: amount representing interest (793) Present value of lease liabilities $ 19,065 (1) Finance lease payments include $3.0 million of future payments required under signed lease agreements that have not yet commenced. Supplemental cash flow information related to the Company's leases was as follows (in thousands): For the three months ended March 31, 2024 2023 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from finance leases $ 351 $ 638 Financing cash flows from finance leases $ 4,292 $ 7,634 Non-cash right-of-use assets obtained in exchange for lease obligations: Finance leases $ 3,138 $ 2,158

Net Income per Share

Net Income per Share	3 Months Ended
	Mar. 31, 2024
Earnings Per Share [Abstract]
Net Income per Share	Net Income per Share Basic and diluted net income per share was calculated as follows (in thousands, except per share data): For the three months ended March 31, 2024 2023 Numerator: Net income $ 136,989 $ 182,277 Denominator: Weighted-average shares used to compute net income per share—basic 52,163 51,842 Dilutive restrictive stock awards 54 114 Weighted-average shares used to compute net income per share—diluted 52,217 51,956 Net income per share—basic $ 2.63 $ 3.52 Net income per share—diluted $ 2.62 $ 3.51

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Environmental Matters The Company is subject to a wide variety of laws and regulations concerning the protection of the environment, both with respect to the construction and operation of its plants, mines and other facilities and with respect to remediating environmental conditions that may exist at its own and other properties. The Company believes it is in compliance with federal, state and local environmental laws and regulations. The Company accrues for environmental expenses resulting from existing conditions that relate to past operations when the costs are probable and can be reasonably estimated. As of March 31, 2024 and December 31, 2023, there were no accruals for environmental matters other than asset retirement obligations for mine reclamation. Miscellaneous Litigation From time to time, the Company is party to lawsuits arising in the ordinary course of business. The Company records costs relating to these matters when a loss is probable and the amount can be reasonably estimated. The effect of the outcome of these matters on the Company’s future results of operations cannot be predicted with certainty as any such effect depends on future results of operations and the amount and timing of the resolution of such matters. As of March 31, 2024 and December 31, 2023, there were no items accrued for miscellaneous litigation. On July 15, 2015, Walter Energy and certain of its wholly owned U.S. subsidiaries, including Jim Walter Resources, Inc. (“JWR”) filed voluntary petitions for relief under chapter 11 of title 11 of the U.S. Bankruptcy Code (the “Chapter 11 Cases”) in the Northern District of Alabama, Southern Division. On December 7, 2015, Walter Energy Canada Holdings, Inc., Walter Canadian Coal Partnership and their Canadian affiliates (collectively “Walter Canada”) applied for and were granted protection under the Companies’ Creditors Arrangement Act (the “CCAA”) pursuant to an Initial Order of the Supreme Court of British Columbia. As a result of the Company’s acquisition of certain core operating assets of Walter Energy during the Chapter 11 Cases, in the first quarter of 2023 the Company received $0.2 million from the Chapter 11 Cases which is reflected as other income in the Condensed Statement of Operations. Other Commitments and Contingencies The Company is party to various transportation and throughput agreements with rail and barge transportation providers and the Alabama State Port Authority. These agreements contain annual minimum tonnage guarantees with respect to coal transported from the mine sites to the Port of Mobile, Alabama, the unloading of rail cars or barges, and the loading of vessels. If the Company does not meet its minimum throughput obligations, which are based on annual minimum amounts, it is required to pay the transportation providers or the Alabama State Port Authority a contractually specified amount per metric ton for the difference between the actual throughput and the minimum throughput requirement. At March 31, 2024 and December 31, 2023, the Company had no liability recorded for minimum throughput requirements. Royalty Obligations

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2024
Equity [Abstract]
Stockholders' Equity	Stockholders' Equity Common Shares The Company is authorized to issue up to 140,000,000 common shares, $0.01 par value per share. Holders of common shares are entitled to receive dividends when authorized by the Board. Stock Repurchase Program On March 26, 2019, the Board approved the Company's second stock repurchase program (the “New Stock Repurchase Program”) that authorizes repurchases of up to an aggregate of $70.0 million of the Company's outstanding common stock. The Company fully exhausted its previous stock repurchase program (the "First Stock Repurchase Program") of $40.0 million of its outstanding common stock. The New Stock Repurchase Program does not require the Company to repurchase a specific number of shares or have an expiration date. The New Stock Repurchase Program may be suspended or discontinued by the Board at any time without prior notice. Under the New Stock Repurchase Program, the Company may repurchase shares of its common stock from time to time, in amounts, at prices and at such times as the Company deems appropriate, subject to market and industry conditions, share price, regulatory requirements and other considerations as determined from time to time by the Company. The Company’s repurchases may be executed using open market purchases or privately negotiated transactions in accordance with applicable securities laws and regulations, including Rule 10b-18 of the Exchange Act and repurchases may be executed pursuant to Rule 10b5-1 under the Exchange Act. Repurchases will be subject to limitations in the ABL Facility and the Indenture. The Company intends to fund repurchases under the New Stock Repurchase Program from cash on hand and/or other sources of liquidity. Any future repurchases of shares of the Company's common stock will be subject to the 1% excise tax under the Inflation Reduction Act. As of March 31, 2024 and December 31, 2023, the Company has repurchased 500,000 shares under the New Stock Repurchase Program for approximately $10.6 million, leaving approximately $59.4 million of share repurchases authorized under the New Stock Repurchase Program. Dividends The Company has declared the following dividends on common shares as of the filing date of this Form 10-Q: Dividend per Share Dividends Paid Dividend Type Declaration Date Record Date Payable Date (in millions) $ 0.07 $ 3.6 Quarterly February 9, 2023 February 20, 2023 February 27, 2023 $ 0.88 $ 46.4 Special February 13, 2023 February 28, 2023 March 7, 2023 $ 0.07 $ 3.7 Quarterly April 25, 2023 May 5, 2023 May 12, 2023 $ 0.07 $ 3.7 Quarterly July 28, 2023 August 7, 2023 August 14, 2023 $ 0.07 $ — Quarterly October 24, 2023 November 3, 2023 November 10, 2023 $ 0.08 $ 4.2 Quarterly February 9, 2024 February 20, 2024 February 26, 2024 $ 0.50 $ 26.3 Special February 9, 2024 March 1, 2024 March 7, 2024 $ 0.08 $ 4.2 Quarterly April 25, 2024 May 6, 2024 May 13, 2024 Preferred Shares The Company is authorized to issue up to 10,000,000 shares of preferred stock, $0.01 par value per share.

Derivative Instruments

Derivative Instruments	3 Months Ended
	Mar. 31, 2024
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments	Derivative Instruments The Company enters into natural gas swap contracts from time to time to hedge the exposure to variability in expected future cash flows associated with the fluctuations in the price of natural gas related to the Company’s forecasted sales. As of March 31, 2024 and December 31, 2023, the Company had no natural gas swap contracts outstanding.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	3 Months Ended
	Mar. 31, 2024
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	Fair Value of Financial Instruments The Company had no significant assets or any other liabilities measured at fair value on a recurring basis as of March 31, 2024 or December 31, 2023. During the three months ended March 31, 2024, there were no transfers between Level 1, Level 2 and Level 3. The Company uses quoted dealer prices for similar contracts in active over-the-counter markets for determining fair value of Level 2 liabilities. There were no changes to the valuation techniques used to measure liability fair values on a recurring basis during the three months ended March 31, 2024. The following methods and assumptions were used to estimate the fair value for which the fair value option was not elected: Cash and cash equivalents, short-term investments, receivables and trade accounts payable — The carrying amounts reported in the Condensed Balance Sheets approximate fair value due to the short-term nature of these assets and liabilities. Debt —

Segment Information

Segment Information	3 Months Ended
	Mar. 31, 2024
Segment Reporting [Abstract]
Segment Information	Segment Information The Company identifies a business as an operating segment if: (i) it engages in business activities from which it may earn revenues and incur expenses; (ii) its operating results are regularly reviewed by the Chief Operating Decision Maker (“CODM”), who is the Company’s Chief Executive Officer, to make decisions about resources to be allocated to the segment and assess its performance; and (iii) it has available discrete financial information. The Company has determined that its two underground mining operations are its operating segments. The CODM reviews financial information at the operating segment level to allocate resources and to assess the operating results and financial performance for each operating segment. Operating segments are aggregated into a reportable segment if the operating segments have similar quantitative economic characteristics and if the operating segments are similar in the following qualitative characteristics: (i) nature of products and services; (ii) nature of production processes; (iii) type or class of customer for their products and services; (iv) methods used to distribute the products or provide services; and (v) if applicable, the nature of the regulatory environment. The Company has determined that the two operating segments are similar in both quantitative and qualitative characteristics and thus the two operating segments have been aggregated into one reportable segment. The Company has determined that its natural gas and royalty businesses and the Blue Creek mine development did not meet the criteria in ASC 280 to be considered as operating or reportable segments. Therefore, the Company has included their results in an “all other” category as a reconciling item to consolidated amounts. The Company does not allocate all of its assets, or its depreciation and depletion expense, selling, general and administrative expenses, transactions costs, interest income (expense), and income tax expense or benefit by segment. The following tables include reconciliations of segment information to consolidated amounts (in thousands): For the three months ended March 31, 2024 2023 Revenues Mining $ 497,998 $ 500,491 All other 5,514 9,183 Total revenues $ 503,512 $ 509,674 For the three months ended March 31, 2024 2023 Capital Expenditures Mining $ 31,019 $ 40,149 All other 68,684 28,030 Total capital expenditures $ 99,703 $ 68,179 The Company evaluates the performance of its segment based on Segment Adjusted EBITDA, which is defined as net income adjusted for other revenues, cost of other revenues, depreciation and depletion, selling, general and administrative, business interruption, idle mine, other income, interest income (expense), net, income tax expense, loss on extinguishment of debt and certain transactions or adjustments that the CODM does not consider for the purposes of making decisions to allocate resources among segments or assessing segment performance. Segment Adjusted EBITDA does not represent and should not be considered as an alternative to cost of sales under GAAP and may not be comparable to other similarly titled measures used by other companies. Below is a reconciliation of Segment Adjusted EBITDA to net income, which is its most directly comparable financial measure calculated and presented in accordance with GAAP (in thousands): For the three months ended March 31, 2024 2023 Segment Adjusted EBITDA $ 212,411 $ 267,861 Other revenues 5,514 9,183 Cost of other revenues (9,965) (11,438) Depreciation and depletion (40,023) (37,213) Selling, general and administrative (18,658) (14,516) Business interruption (201) (4,217) Other income — 221 Interest income, net 7,033 1,460 Income tax expense (19,122) (29,064) Net income $ 136,989 $ 182,277

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Pay vs Performance Disclosure
Net income	$ 136,989	$ 182,277

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Mar. 31, 2024 shares
Trading Arrangements, by Individual
Non-Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Terminated	false
Jack K. Richardson [Member]
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	On February 26, 2024, Jack K. Richardson, Chief Operating Officer of the Company, adopted a Rule 10b5-1 trading plan intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) under the Exchange Act (a "Rule 10b5-1 Plan"). Mr. Richardson's plan, which provides for the potential sale of up to 117,005 shares of the Company's common stock, terminates upon the earlier of December 31, 2025 or the date all shares subject to the plan have been sold. In addition, on February 27, 2024, Mr. Richardson terminated the previous Rule 10b5-1 Plan entered into on November 7, 2023, which provided for the potential sale of up to 88,000 shares of the Company's common stock.
Name	Jack K. Richardson
Title	Chief Operating Officer
Adoption Date	February 26, 2024
Arrangement Duration	674 days
February 2024 Plan [Member] | Jack K. Richardson [Member]
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	true
Aggregate Available	117,005
November 2023 Plan [Member]
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Terminated	false
November 2023 Plan [Member] | Jack K. Richardson [Member]
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	true
Aggregate Available	88,000

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2024
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation
Use of Estimates	Use of Estimates
Cash and Cash Equivalents	Cash and Cash Equivalents
Short-Term Investments	Short-Term Investments Instruments with maturities greater than three months, but less than twelve months, are included in short-term investments. The Company also purchases fixed income securities and certificates of deposits with varying maturities that are classified as available for sale and are carried at fair value. Securities classified as held to maturity are those securities that management has the intent and ability to hold to maturity.
Revenue Recognition	Revenue Recognition Revenue is recognized when performance obligations under the terms of a contract with the Company's customers are satisfied; for all contracts this occurs when control of the promised goods have been transferred to the Company's customers and risk of loss passes such customers. For coal shipments to domestic customers via rail, control is transferred when the railcar is loaded. For coal shipments to international customers via ocean vessel, control is transferred when the vessel is loaded at the Port of Mobile in Alabama. Occasionally, the Company will sell coal stockpiles at the barge loadout or port upon which control, title and risk of loss transfers when stockpiles are segregated. For all steelmaking coal sales under average pricing contracts where pricing is not finalized when revenue is recognized, revenue is recorded based on estimated consideration to be received at the date of the sale. For natural gas sales, control is transferred when the gas has been transferred to the pipeline. Revenue is disaggregated between coal sales within the Company's mining segment and natural gas sales included in all other revenues, as disclosed in Note 12. The Company's coal and gas sales generally include up to 45-day payment terms following the transfer of control of the goods to the customer. The Company typically does not include extended payment terms in its contracts with customers.
Trade Accounts Receivable and Allowance for Credit Losses	Trade Accounts Receivable and Allowance for Credit Losses Trade accounts receivable are stated at cost. Trade accounts receivable represent customer obligations that are derived from revenue recognized from contracts with customers. Credit is extended based on an evaluation of the individual customer's financial condition. The Company maintains trade credit insurance on the majority of its customers and the geographic regions of coal shipments to these customers. In some instances, the Company requires letters of credit, cash collateral or prepayments from its customers on or before shipment to mitigate the risk of loss. These efforts have consistently resulted in the Company recognizing no historical credit losses. The Company also has never had to have a claim against its trade credit insurance policy. In order to estimate the allowance for credit losses on trade accounts receivable, the Company utilizes an aging approach in which potential impairment is calculated based on how long a receivable has been outstanding (e.g., current, 1-31 days, 31-60 days, etc.). The Company calculates an expected credit loss rate based on the Company’s historical credit loss rate, the risk characteristics of its customers, and the current steelmaking coal and steel market environments. As of March 31, 2024 and December 31, 2023, the estimated allowance for credit losses was immaterial and did not have a material impact on the Company's financial statements.

Inventories, net (Tables)

Inventories, net (Tables)	3 Months Ended
	Mar. 31, 2024
Inventory Disclosure [Abstract]
Schedule of Inventories, Net	Inventories, net are summarized as follows (in thousands): March 31, 2024 December 31, 2023 Coal $ 110,438 $ 129,989 Raw materials, parts, supplies and other, net 55,212 53,960 Total inventories, net $ 165,650 $ 183,949

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 31, 2024
Debt Disclosure [Abstract]
Schedule of Long-Term Debt Instruments	The Company's debt consisted of the following (in thousands): March 31, 2024 December 31, 2023 Weighted Average Interest Rate Final Maturity Senior Secured Notes $ 156,517 $ 156,517 7.875% December 2028 ABL Borrowings — — Varies (1) December 2026 Debt discount (3,351) (3,494) Total debt 153,166 153,023 Less: current debt — — Total long-term debt $ 153,166 $ 153,023 (1) Borrowings under the ABL Facility bear interest at a rate equal to Secured Overnight Financing Rate ("SOFR") ranging from 1.5% to 2.0%, plus a credit adjustment spread, ranging currently from 0.11448% to 0.42826%, or an alternate base rate plus an applicable margin, which is determined based on the average availability of the commitments under the ABL Facility, ranging from 0.5% to 1.0%.

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2024
Leases [Abstract]
Schedule of Supplemental Balance Sheet Information	Supplemental balance sheet information related to leases was as follows (in thousands): March 31, 2024 December 31, 2023 Finance lease right-of-use assets, net (1) $ 64,406 $ 67,014 Finance lease liabilities Current 11,357 11,463 Noncurrent 7,708 8,756 Total finance lease liabilities $ 19,065 $ 20,219 Weighted average remaining lease term - finance leases (in months) 20.0 20.8 Weighted average discount rate - finance leases (2) 7.02 % 7.02 % (1) Finance lease right-of-use assets are recorded net of accumulated amortization of $42.2 million and $38.5 million and are included in property, plant and equipment, net in the Condensed Balance Sheets as of March 31, 2024 and the Balance Sheets as of December 31, 2023, respectively. (2)
Schedule of Components of Lease Expense	The components of lease expense were as follows (in thousands): For the three months ended March 31, 2024 2023 Operating lease cost (1) : $ 12,606 $ 6,430 Finance lease cost: Amortization of leased assets 5,758 5,280 Interest on lease liabilities 351 638 Net lease cost $ 18,715 $ 12,348 (1) Includes leases that are for periods of 12 months or less.
Schedule of Maturities of Lease Liabilities	Maturities of lease liabilities for the Company's finance leases as of March 31, 2024 were as follows (in thousands): Finance Leases (1) 2024 $ 14,208 2025 4,598 2026 1,052 2027 — Thereafter — Total 19,858 Less: amount representing interest (793) Present value of lease liabilities $ 19,065 (1) Finance lease payments include $3.0 million of future payments required under signed lease agreements that have not yet commenced.
Schedule of Supplemental Cash Flow Information Related to Leases	Supplemental cash flow information related to the Company's leases was as follows (in thousands): For the three months ended March 31, 2024 2023 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from finance leases $ 351 $ 638 Financing cash flows from finance leases $ 4,292 $ 7,634 Non-cash right-of-use assets obtained in exchange for lease obligations: Finance leases $ 3,138 $ 2,158

Net Income per Share (Tables)

Net Income per Share (Tables)	3 Months Ended
	Mar. 31, 2024
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	Basic and diluted net income per share was calculated as follows (in thousands, except per share data): For the three months ended March 31, 2024 2023 Numerator: Net income $ 136,989 $ 182,277 Denominator: Weighted-average shares used to compute net income per share—basic 52,163 51,842 Dilutive restrictive stock awards 54 114 Weighted-average shares used to compute net income per share—diluted 52,217 51,956 Net income per share—basic $ 2.63 $ 3.52 Net income per share—diluted $ 2.62 $ 3.51

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2024
Equity [Abstract]
Schedule of Dividends on Common Shares	The Company has declared the following dividends on common shares as of the filing date of this Form 10-Q: Dividend per Share Dividends Paid Dividend Type Declaration Date Record Date Payable Date (in millions) $ 0.07 $ 3.6 Quarterly February 9, 2023 February 20, 2023 February 27, 2023 $ 0.88 $ 46.4 Special February 13, 2023 February 28, 2023 March 7, 2023 $ 0.07 $ 3.7 Quarterly April 25, 2023 May 5, 2023 May 12, 2023 $ 0.07 $ 3.7 Quarterly July 28, 2023 August 7, 2023 August 14, 2023 $ 0.07 $ — Quarterly October 24, 2023 November 3, 2023 November 10, 2023 $ 0.08 $ 4.2 Quarterly February 9, 2024 February 20, 2024 February 26, 2024 $ 0.50 $ 26.3 Special February 9, 2024 March 1, 2024 March 7, 2024 $ 0.08 $ 4.2 Quarterly April 25, 2024 May 6, 2024 May 13, 2024

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2024
Segment Reporting [Abstract]
Schedule of Reconciliation of Revenue from Segments to Consolidated	The following tables include reconciliations of segment information to consolidated amounts (in thousands): For the three months ended March 31, 2024 2023 Revenues Mining $ 497,998 $ 500,491 All other 5,514 9,183 Total revenues $ 503,512 $ 509,674
Schedule of Reconciliation of Capital Expenditures from Segments to Consolidated	For the three months ended March 31, 2024 2023 Capital Expenditures Mining $ 31,019 $ 40,149 All other 68,684 28,030 Total capital expenditures $ 99,703 $ 68,179
Schedule of Reconciliation of Net Income (Loss) from Segments to Consolidated	Below is a reconciliation of Segment Adjusted EBITDA to net income, which is its most directly comparable financial measure calculated and presented in accordance with GAAP (in thousands): For the three months ended March 31, 2024 2023 Segment Adjusted EBITDA $ 212,411 $ 267,861 Other revenues 5,514 9,183 Cost of other revenues (9,965) (11,438) Depreciation and depletion (40,023) (37,213) Selling, general and administrative (18,658) (14,516) Business interruption (201) (4,217) Other income — 221 Interest income, net 7,033 1,460 Income tax expense (19,122) (29,064) Net income $ 136,989 $ 182,277

Business and Basis of Present_2

Business and Basis of Presentation (Details) - USD ($) $ in Thousands		3 Months Ended
	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Business interruption		$ 201	$ 4,217
Gas Wells
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Payments to acquire equity method investments	$ 2,400

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Short-Term Investments (Narrative) (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Schedule of Held-to-maturity Securities [Line Items]
Short-term investments	$ 9,149	$ 9,030
Cash and Fixed Income Securities
Schedule of Held-to-maturity Securities [Line Items]
Short-term investments	$ 9,100	$ 9,000

Inventories, net (Details)

Inventories, net (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Inventory Disclosure [Abstract]
Coal	$ 110,438	$ 129,989
Raw materials, parts, supplies and other, net	55,212	53,960
Total inventories, net	$ 165,650	$ 183,949

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Income Tax Disclosure [Abstract]
Income tax expense	$ 19,122	$ 29,064

Debt - Schedule of Long-Term De

Debt - Schedule of Long-Term Debt Instruments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Debt discount	$ (3,351)	$ (3,494)
Total debt	153,166	153,023
Less: current debt	0	0
Total long-term debt	153,166	153,023
ABL Borrowings
Debt Instrument [Line Items]
Long-term debt, gross	$ 0	0
ABL Borrowings | Minimum | Secured Overnight Financing Rate
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)	1.50%
ABL Borrowings | Minimum | Credit Adjustment Spread
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)	0.11448%
ABL Borrowings | Minimum | Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)	0.50%
ABL Borrowings | Maximum | Secured Overnight Financing Rate
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)	2%
ABL Borrowings | Maximum | Credit Adjustment Spread
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)	0.42826%
ABL Borrowings | Maximum | Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)	1%
Senior Secured Notes | Senior Secured Notes
Debt Instrument [Line Items]
Long-term debt, gross	$ 156,517	$ 156,517

Debt - Narrative (Details)

Debt - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2023	Nov. 15, 2026	Mar. 31, 2024	Dec. 31, 2023	Dec. 06, 2021
Senior Secured Notes
Debt Instrument [Line Items]
Extinguishment of debt, amount	$ 8,000,000
Loss on early extinguishment of debt	$ 100,000
Senior Secured Notes | Senior Secured Notes
Debt Instrument [Line Items]
Face amount of debt					$ 350,000,000
Stated interest rate (as a percent)			7.875%
Percentage of initial price					99.343%
Senior Secured Notes | Senior Secured Notes Due 2024, Existing Notes
Debt Instrument [Line Items]
Stated interest rate (as a percent)					8%
ABL Borrowings | Citibank
Debt Instrument [Line Items]
Amount of borrowings available			$ 107,400,000	$ 107,400,000
ABL Borrowings | Citibank
Debt Instrument [Line Items]
Aggregate lender commitment					$ 65,000,000
Aggregate principal amount drawn			0
ABL Borrowings | Second Amended And Restated Credit Agreement | Citibank | Forecast
Debt Instrument [Line Items]
Aggregate lender commitment		$ 116,000,000
ABL Borrowings | Letter of Credit | Citibank
Debt Instrument [Line Items]
Letters of credit outstanding			$ 8,700,000	$ 8,700,000

Leases - Narrative (Details)

Leases - Narrative (Details)	Mar. 31, 2024
Minimum
Lessor, Lease, Description [Line Items]
Remaining lease terms	1 year
Maximum
Lessor, Lease, Description [Line Items]
Remaining lease terms	5 years

Leases - Schedule of Supplement

Leases - Schedule of Supplemental Balance Sheet Information (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Leases [Abstract]
Finance lease right-of-use assets, net	$ 64,406	$ 67,014
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Property, plant and equipment, net	Property, plant and equipment, net
Finance lease liabilities
Current	$ 11,357	$ 11,463
Noncurrent	7,708	8,756
Total finance lease liabilities	$ 19,065	$ 20,219
Weighted average remaining lease term - finance leases (in months)	1 year 8 months 1 day	1 year 8 months 23 days
Weighted average discount rate - finance leases (as a percent)	7.02%	7.02%
Accumulated amortization	$ 42,200	$ 38,500

Leases - Schedule of Components

Leases - Schedule of Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Leases [Abstract]
Operating lease cost	$ 12,606	$ 6,430
Finance lease cost:
Amortization of leased assets	5,758	5,280
Interest on lease liabilities	351	638
Net lease cost	$ 18,715	$ 12,348

Leases - Schedule of Maturities

Leases - Schedule of Maturities of Lease Liabilities (Details) $ in Thousands	Mar. 31, 2024 USD ($)
Leases [Abstract]
2024	$ 14,208
2025	4,598
2026	1,052
2027	0
Thereafter	0
Total	19,858
Less: amount representing interest	(793)
Present value of lease liabilities	19,065
Future payments required under signed lease agreements that have not yet commenced	$ 3,000

Leases - Schedule of Suppleme_2

Leases - Schedule of Supplemental Cash Flow Information Related to Leases (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from finance leases	$ 351	$ 638
Financing cash flows from finance leases	4,292	7,634
Non-cash right-of-use assets obtained in exchange for lease obligations:
Finance leases	$ 3,138	$ 2,158

Net Income per Share (Details)

Net Income per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Numerator:
Net income	$ 136,989	$ 182,277
Denominator:
Weighted-average shares used to compute net income per share-basic (in shares)	52,163	51,842
Dilutive restrictive stock awards (in shares)	54	114
Weighted-average shares used to compute net income per share-diluted (in shares)	52,217	51,956
Net income per share-basic (in dollars per share)	$ 2.63	$ 3.52
Net income per share-diluted (in dollars per share)	$ 2.62	$ 3.51

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Settlement proceeds		$ 200,000
Throughput obligation	$ 0		$ 0
Coal royalty expense	$ 42,900,000	$ 33,200,000

Stockholders' Equity - Narrativ

Stockholders' Equity - Narrative (Details) - USD ($)	3 Months Ended	6 Months Ended
	Mar. 31, 2024	Jun. 30, 2023	Dec. 31, 2023	Mar. 26, 2019	May 02, 2018
Class of Stock [Line Items]
Common stock authorized (in shares)	140,000,000		140,000,000
Common stock, par value (in dollars per share)	$ 0.01		$ 0.01
Preferred stock authorized (in shares)	10,000,000		10,000,000
Preferred stock, par value (in dollars per share)	$ 0.01		$ 0.01
New Stock Repurchase Program
Class of Stock [Line Items]
Authorized amount of stock to be repurchased, value				$ 70,000,000
Shares repurchased (in shares)	500,000	500,000
Shares repurchased, value	$ 10,600,000	$ 10,600,000
Remaining authorized repurchase amount	$ 59,400,000		$ 59,400,000
The First Stock Repurchase Program
Class of Stock [Line Items]
Authorized amount of stock to be repurchased, value					$ 40,000,000

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Dividends on Common Shares (Details) - USD ($) $ / shares in Units, $ in Thousands

3 Months Ended

May 06, 2024

Apr. 25, 2024

Mar. 01, 2024

Feb. 20, 2024

Feb. 09, 2024

Nov. 10, 2023

Oct. 24, 2023

Aug. 14, 2023

Jul. 28, 2023

May 12, 2023

Apr. 25, 2023

Mar. 07, 2023

Feb. 27, 2023

Feb. 13, 2023

Feb. 09, 2023

Mar. 31, 2024

Mar. 31, 2023

Class of Stock [Line Items]

Dividends Paid

$ 30,638

$ 50,016

Quarterly Dividend

Class of Stock [Line Items]

Dividend per Share (in dollars per share)

$ 0.08

$ 0.07

$ 0.07

$ 0.07

$ 0.07

Dividends Paid

$ 4,200

$ 0

$ 3,700

$ 3,700

$ 3,600

Quarterly Dividend | Forecast

Class of Stock [Line Items]

Dividends Paid

$ 4,200

Quarterly Dividend | Subsequent Event

Class of Stock [Line Items]

Dividend per Share (in dollars per share)

$ 0.08

Special Dividend

Class of Stock [Line Items]

Dividend per Share (in dollars per share)

$ 0.50

$ 0.88

Dividends Paid

$ 26,300

$ 46,400

Derivative Instruments (Details

Derivative Instruments (Details)	3 Months Ended
	Mar. 31, 2024 USD ($)	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($) derivative_instrument
Derivative [Line Items]
Gain (loss) on derivatives	$ 0	$ 500,000
Natural gas swap contracts, current asset	0		$ 0
Natural gas swap contracts, current liability	0		$ 0
Natural Gas | Swap | Not Designated as Hedging Instrument
Derivative [Line Items]
Derivative contracts outstanding | derivative_instrument			0
Natural Gas | Commodity Contract | Not Designated as Hedging Instrument
Derivative [Line Items]
Gain (loss) on derivatives	$ 0	(700,000)
Realized gain		$ 200,000

Fair Value of Financial Instr_2

Fair Value of Financial Instruments - Narrative (Details) - USD ($)	Mar. 31, 2024	Dec. 31, 2023
Senior Secured Notes Due 2024, Existing Notes | Senior Secured Notes | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of debt instrument	$ 157,700,000	$ 156,000,000
Citibank | ABL Borrowings
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amount of borrowings available	107,400,000	107,400,000
ABL Borrowings | Citibank
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Outstanding debt under ABL Facility	0	0
ABL Borrowings | Citibank | Letter of Credit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Letters of credit outstanding	$ 8,700,000	$ 8,700,000

Segment Information - Narrative

Segment Information - Narrative (Details)	3 Months Ended
	Mar. 31, 2024 segment
Segment Reporting [Abstract]
Number of operating segments	2
Number of reportable segments	1

Segment Information - Schedule

Segment Information - Schedule of Reconciliation of Revenue from Segments to Consolidated (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Segment Reporting Information [Line Items]
Total revenues	$ 503,512	$ 509,674
Segment Reconciling Items
Segment Reporting Information [Line Items]
Total revenues	5,514
Mining | Operating Segments
Segment Reporting Information [Line Items]
Total revenues	$ 497,998

Segment Information - Schedul_2

Segment Information - Schedule of Reconciliation of Capital Expenditures from Segments to Consolidated (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Segment Reporting Information [Line Items]
Capital Expenditures	$ 99,703	$ 68,179
Segment Reconciling Items
Segment Reporting Information [Line Items]
Capital Expenditures	68,684	28,030
Mining | Operating Segments
Segment Reporting Information [Line Items]
Capital Expenditures	$ 31,019	$ 40,149

Segment Information - Schedul_3

Segment Information - Schedule of Reconciliation of Net Income (Loss) from Segments to Consolidated (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenue from External Customer [Line Items]
Segment Adjusted EBITDA	$ 212,411	$ 267,861
Other revenues	503,512	509,674
Cost of other revenues	(9,965)	(11,438)
Depreciation and depletion	(40,023)	(37,213)
Selling, general and administrative	(18,658)	(14,516)
Business interruption	(201)	(4,217)
Other income	0	221
Interest expense	7,033	1,460
Income tax expense	(19,122)	(29,064)
Net income	136,989	182,277
Other revenues
Revenue from External Customer [Line Items]
Other revenues	$ 5,514	$ 9,183